Hair care kits, such as kits for dyeing or permanent waving of hair at home, often contain instructions advising the user that a skin sensitivity test should be carried out before the kit is used. This is to determine whether the user of the kit may be sensitive to, or allergic to, any of the component chemicals of the kit.

These sensitivity tests usually involve cleaning a small area of the skin, usually with soap and water, and applying to this cleaned area a little of the relevant chemical. The chemical may be allowed to dry and may be reapplied a further two or three times. The user is instructed not to wash the area of skin to which the chemical is applied and to wait a period of 48 hours to determine whether there is any reaction to the test chemicals. If there is any irritation to the skin after the 48 hour period, the user is advised not to use the kit; however, if there is no irritation then the user may proceed to carry out hair treatment.

One of the problems with currently used sensitivity tests is that the user is instructed not to wash the area of skin where the chemical has been applied for two whole days. This can prove very difficult and the user may inadvertently remove the chemical from the skin thereby falsely giving a negative result.

This could prove dangerous as the user would be led to believe that it would be safe to continue to use the kit. Furthermore, the user will probably be required to wear gloves when applying the solution to the skin. As kits of this kind are usually only provided with a single pair of gloves, the user may be required to re-use the same pair of (possibly soiled) gloves when carrying out the actual treatment.

WO-A-91/11132 discloses an allergic response indicator which comprises a"cutaneous three-dimensional contact adhesive polymeric sheet capable of self-adherence to the epidermis of a subject and containing an allergic indicator compound distributed throughout the polymeric sheet which, when applied to the epidermis, is releasable thereto over the period of application".

The document states that the indicator compound may be a hair colouring agent, such as a para-phenylene diamine, which is both a hair colour and"an indicator of the likelihood that a particular subject will be sensitive to related hair colouring agents".

However, modern hair colouring chemicals are generally complex mixtures, usually in one or more packs. One or more of the packs may contain further phenylene diamines or salts thereof (and sensitivity to para-phenylene diamine is not conclusive of sensitivity to any other phenylene diamines), other amines or ammonia, phenols (in particular, resorcinols), peroxides or the like. Any of the ingredients may induce an allergic response in at least some individuals.

The aim of the present invention is to alleviate some of the aforementioned problems and to provide a quick and easy- to-use sensitivity test.

According to the present invention there is provided a hair care kit suitable for home use, which kit comprises: (a) a first sealed container containing at least one first hair treatment chemical; (b) at least one second sealed container containing at least one second hair treatment chemical different to the first hair treatment chemical; (c) at least one patch having a skin contact face adapted to be secured to the skin of a user; (d) at least one first reservoir containing in releasable form a supply of said first hair treatment chemical, said first reservoir being present in at least one of said patches and adapted to release said first chemical through the respective skin contact face thereof; (e) at least one second reservoir containing in releasable form a supply of said second hair treatment chemical, said second reservoir being present in at least one of said patches and adapted to release said second chemical through the respective skin contact face thereof, each of said first reservoirs and second reservoirs being such that flow of liquid is precluded either from a first reservoir to a second reservoir, or vice versa, at least until the respective patch or patches are applied to the skin of the user.

The patch or patches used in the kit according to the present invention may be suitable for use on various parts of the body. Such a patch preferably resembles an adhesive plaster dressing and comprises an upper surface and an undersurface. The upper surface of each such patch preferably comprises a thin, water-resistant, flexible plastics material. This allows the user to wash without fear of affecting the result of the sensitivity test. The undersurface of the respective patch (that is the surface to be located adjacent the skin) typically comprises a thin, water-resistant, flexible plastics material coated with an adhesive polymer to enable the patch to adhere to the skin until the user wishes its removal. The undersurface of the patch further comprises a contact pad designed to permit sustained or accelerated release any chemicals impregnated thereupon or therein. The water-resistant nature of such a flexible plastics material ensures that the chemicals remain on the pad and do not permeate out.

The first and second containers may be, for example, in the nature of bottles, sachets, flexible tubes or the like.

The containers should contain an order of magnitude more of the respective chemicals than is present in the respective reservoirs in the relevant patches (such as at least ten times the amount thereof).

The first and second reservoirs of the respective chemicals may be on separate patches; alternatively, they may be provided on the same patch either in separate areas or in overlapping areas providing contact between the first and second chemicals is inhibited until the respective patch contacts the skin of the user. In some embodiments, the respective chemicals may be provided in rupturable microcapsules or the like (analogous to the types of microcapsules conventionally employed in pressure-sensitive copying paper or the like.

The chemicals are typically hair colours (which may be of a type conventionally classified as temporary, semi-permanent, demi-permanent or permanent). A further category is what is known as a gradual or progressive dye. Such chemicals are generally in the form of liquids or semi-solids (rinses, gels, mousses or sprays, for example). The relevant container is chosen depending on the nature of the chemicals employed.

The or each patch may, if wished, have printed thereon indicia (such as instructions for use, pictorial representations or the like), and brand indications or the like; alternatively, the patch may be attached to a sheet having instructions thereon.

Preferably, the hair care kit according to the invention includes at least two further separate receptacles, a first of which contains a small aliquot of the first hair treatment chemical and a second of which contains a small aliquot of the second hair treatment chemical. The chemicals in such receptacles may be used for carrying out a strand test on the hair of a user; the receptacles are themselves preferably sealed in a liquid-tight manner.

Preferably, the hair care kit according to the invention includes at least one swab. This may be used to clean the surface of the skin prior to applying the skin patch; the swab may contain an alcohol and/or an antiseptic or the like.

According to a preferred embodiment of the present invention the swab and skin patch are packaged together in a flexible sheet material, such as printed or plain plastics material and/or laminated barrier material. The swab and patch may be separated from one another by a portion of the sheet material having perforations or the like. Alternatively, the swab and skin patch may be mounted one on top of the other.

The hair care kit according to the invention preferably includes at least one pair of gloves, such as film gloves of polymeric film, which the user can wear when applying the chemicals to the hair.

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 (not to scale) illustrates the upper surface of a skin patch for use in a hair care kit according to the invention; Figure 2 illustrates the undersurface of the skin patch shown in Figure 1; Figure 3 is a plan view of a patch for use in the kit according the invention; and Figure 4 is a side elevation of a patch according to the invention.

Referring first to Figure 1, there is shown a skin patch 1, comprising a flexible, water-resistant material 2.

Referring to Figure 2, there is shown a skin patch 1, comprising a flexible, water-resistant material with adin adhesive polymeric layer 3 and a pad comprising material 4 impregnated with a chemical or chemicals.

Referring to Figure 3, there is shown a patch having a central area 9 containing reservoir of a first chemical and an outer area 10 containing a second chemical.

Referring to Figure 4, the patch illustrated (for use in an exemplary kit according to the invention) comprises a peelable layer 8, an adhesive layer 7 and layers 5 and 6 each impregnated with a respective hair treatment chemical, for release when the patch is contacted with the skin.

When carrying out the method according to the present invention, at least one patch (such as one of the patches described above with reference to the drawings) is applied to a skin surface, preferably to an area of skin where the patch is unlikely to come away or become detached, so as to allow release of the respective chemicals therefrom.

The patch is then left on the skin for a suitable time and then removed. If irritation or redness is observed, then the relevant individual is advised not to use the contents of a kit containing the same chemical or chemicals on the hair.

If there is no visible irritation then the user may proceed to dye or permanently wave their hair.